dimensional changes in alveolar ridge preservation

Conditions: Alveolar Bone Loss

Summary: objective: the objective is to evaluate the dimensional changes of soft tissue and alveolar ridge after extraction of posterior elements with different clinical protocols of alveolar preservation.

detailed methodology: 80 individuals will be selected with need for extraction of premolar and molar elements, from both arches, for non-periodontal reasons, to participate in this randomized controlled clinical study. the dental elements will be extracted atraumatically, and allocated to one of the study groups (n=20/grp): control group (ctl): alveolus closure with total flap elevation and simple suture; group free gingival mixed graft (eglm): closure of the alveolus without flap elevation, and placement of a mixed free gingival tissue graft (epithelialized in the central region and de-epithelialized (2 mm) in the vestibulolingual edges; bone + mixed free gum graft group (b+eglm): socket closure without flap elevation, placement of lyophilized bone graft and socket sealing with mixed free gingival tissue graft (as previously described); bone + titanium seal group (b+ts): socket closure without flap elevation, placement of lyophilized bone graft, socket sealing by installing a non-absorbable titanium membrane. immediately after the extractions, cone beam computed tomography (90 kvp/8 ma/2.3 sec) will be performed, with lip/cheek separation, with 1.5 mm thick slices and a 1 mm distance, with a field of vision (fov) of 5±5 cm, which will be repeated after 6 months. during the ct scans, the patients will use intra-oral appliances with hyperdense indicators to determine the reference points to measure the variables: bone tissue height in the center of the socket (primary variable) and every 2 mm equidistantly; thickness of bone tissue in the center of the socket and every 2 mm equidistantly. soft tissue variables will also be evaluated, such as: mucosal thickness at the height and 2 mm below the edge margin (by ct); height of the keratinized tissue (measured by a dry tip caliper). after 6 months, all patients will receive dental implants, with the ideal measurements for bone dimension, and the possibility of installing implants \>10mm or \<10mm in length will be statistically analyzed. after 4 months of dental implant placement, single prostheses will be installed and ct, soft tissue measurements and clinical parameters will be repeated (peri-implant depth; presence of biofilm and bleeding on probing; tissue thickness at the margin and 2 mm below; keratinized tissue). implants will be re-evaluated after 12 months. all measurements will be performed by a previously calibrated examiner (intra-class correlation above 90%). the data will initially be analyzed in a descriptive way, with means and standard deviations. for comparison between groups and times, two-way/tukey anova test will be used. in all analyses, a significance level of 5% will be considered.

Eligibility criteria:
inclusion criteria: * systemic health (hypertension and diabetes controlled) * indication of tooth extraction with at least 2/3 of the bone support, in the premolar or molar region * signing the consent form * individuals over 18 years of age. exclusion criteria: * presence of periodontal disease at the time of surgery * pregnant and lactating women * smokers * being in orthodontic treatment * use medication that alters the bone healing process, such as those used to treat osteoporosis and the bisphosphonate group * individuals under 18 years of age